Extreme heat in tropical and semi-tropical regions is usually accompanied by extremes of high humidity, especially at low altitude where bayous, marshlands, swamps, shallow lakes, heavy vegetations, and forests are abundant; tropical islands, such as the islands of the Caribbean Sea; arid land and deserts nearby oceans shorelines or seashores; such as the regions East of the red Sea and West of the Gulf on the Arabian Peninsula. Generally, natural freshwater resources are scarce or limited in very hot and humid arid areas by or near shorelines due to low precipitation and rainfall and high salinity of underground water.
Shortage in supply of potable water and freshwater is increasing at a vast rate as deserts expand and overtake fertile land and as many of the natural ground water resources are being depleted. Shift in global weather patterns throughout time resulted in a drop in the rate of rainfall in many populated areas. In addition, large cities are expanding at a fast pace, swallowing neighboring villages and small towns, leading to drastic change in the lifestyle of inhabitants of regions of extreme high temperatures and humidity. With the shift from rural to urban lifestyle, people are forced to live in crowded housing and congested apartments with no or little opportunities to fresh air, thus suffering from stuffiness, heat and humidity, and being more exposed to an increasing shortage of freshwater supply.
Accordingly, there is a great need in most new residential developments in hot humid regions for easy access to sufficient freshwater supply as well as for means to cool and dry indoor atmosphere to a level that is barely adequate for leading a healthy and relatively comfortable existence in the dwellings of people with limited resources. Luckily, the lifestyle of people in most of the hot humid regions is such that residents do not require great reduction in temperature or humidity to lead a comfortable life in their housing or work environment.
Water condensation from humid hot air takes place as part of any air conditioning or air drying cycle employed in the wide spread commercial devices used in apartment buildings, residential homes, industrial facilities and commercial establishments. Usually the condensate from such devices drips out and is customarily disposed of as useless wastewater. Naturally, collection and treatment of the drained condensate can provide a continuous source of freshwater.
The prior art includes different configurations of air conditioning devices and systems which collect the water condensed from the air as it is cooled by the air conditioner.
Some such systems are disclosed in Applicant's U.S. Pat. No. 6,481,232, and include window mounted, wall mounted, and centralized embodiments for air conditioning and production of freshwater and drinking water by condensation of water vapor from the air being cooled. Most of the embodiments of this prior patent collect water from circulating indoor air when operated in a cooling mode circulating indoor air and/or water from outdoor air entering the indoor environment when operated in a ventilation mode. One central air conditioning embodiment employs two refrigerant loops, one for cooling and dehumidifying outdoor air and another for cooling and dehumidifying air that has been circulated through the indoor space, thus increasing water producing capacity by processing hot, humid outdoor air, but at the cost of increased system size and duplicated equipment.
U.S. Pat. No. 6,755,037 teaches potable water extraction systems, including embodiments intended for incorporation into an existing central air conditioning system. One such embodiment adds an additional refrigerant evaporator to the air conditioner's refrigeration circuit and positions this over a water collection tray in a separate duct fed by the existing ductwork. Valves are used in the refrigeration circuit to give user-selection over which of the two refrigerant evaporators is in use, either the original air conditioning evaporator for cooling the house, the newly added evaporator for generating and collecting water. This embodiment is thus operable to perform only one of indoor cooling or water production at any given time. Another embodiment avoids the need for an extra evaporator by instead only adding a water collection arrangement beneath the air conditioning's existing evaporator, but therefore is only operable to produce and collect water when the indoor environment is being cooled.
Applicant has developed a unique system which is operable to condense water from outdoor atmospheric air in both a cooling mode and a water-producing mode in an energy and equipment efficient manner.